Rows of orange dots. Small black spot on caudal fin. Replaced by O. halli (slighty larger tail spot) in the Red Sea.
Size : 9 cm
Habitat : In coral-rich, clear lagoons and outreefs, 1-30 m. In pairs or small groups, always swims just above or between coral. Exclusively feeds and Acropora coral polyps.
Distribution : East Africa to S Japan, Samoa and Tonga.